1. Field of the Invention
This invention relates to the field of fenestration products. More particularly, the invention is concerned with locks that join together intersecting members of a metal clad frame to provide a rigid corner that can be injected with sealant to produce an environmental seal along the miter joint between the two members.
2. Description of the Prior Art
In prior art fenestration products such as doors and windows, an open, rectangular metal clad frame is often secured to the outer edge of a box-like, rectangular, wooden framework. The clad frame consists of four separate extruded members that intersect one another at right angles to form the open rectangle. At each corner of the rectangle, the ends of the members are complementally beveled to produce a miter joint. An internal, generally L-shaped, plastic body spans the joint and is fastened to the two members to hold the corner together. The two oppositely projecting legs of each body complementally fit into the somewhat tubular open ends of the extruded members.
In the prior art the right angle legs of the body intersect one another at a diagonally extending, central channel that extends along the back, top, and front of the body. This channel directly underlies and registers with the miter interface line between the two abutting ends of the members at the corner and may be injected with sealant for the purpose of providing an environmental seal under the interface line.
Because of its location in direct registration with the interface line, the channel of the prior art corner lock sometimes allows sealant to escape through the interface line and onto a decorative exterior surface of the product, detracting from its aesthetic appeal. This requires extra material to compensate for the escaped sealant and extra labor to clean the sealant from the decorative surface, leading to higher manufacturing costs.
The present invention solves the problems mentioned above and provides a distinct advance in the state of the art. In particular, the corner lock hereof not only serves the primary function of tightly holding together the metal cladding members at the corner, but also provides a way of achieving a secure environmental seal without allowing sealant to escape through the miter interface line onto the decorative surface of the cladding. In addition, the lock is configured to cooperate with the cladding members during factory assembly to provide a small outlet through which sealant being injected can also flow back out onto the non-decorative surface of the glazing flange of the cladding to form an exterior, diagonal sealing bead along the miter interface line at that location.
The preferred corner lock comprises a generally L-shaped body of resinous material having a pair of intersecting, symmetrical legs with a junction therebetween. The legs are configured for snug reception in the open ends of respective adjacent frame members. The legs are designed to position the junction in direct underlying registration with the miter interface line when the frame members are coupled together by the corner lock. Instead of a single, central channel directly underlying the interface line, the lock has a pair of parallel sealant receiving channels offset from the interface line on opposite lateral sides thereof. When the two channels fill with sealant, they thus define two separate, parallel lines of seal that are spaced away from the interface line a sufficient distance as to keep sealant from reaching the interface line and escaping therethrough. The two lines of seal at each corner prevent any outside moisture that enters the interface line from traveling past the sealant channels and into the interiors of the frame members. A pair of resilient deflection ribs positioned between respective sealing channels and the interface line are configured to engage the interior surface of the corresponding frame members and thereby keep sealant from overflowing the channels and reaching the interface line.
On the back of the body, corresponding to the xe2x80x9cconvexxe2x80x9d outside angle of the corner, the two sealing channels intersect at a centrally disposed void located near the bottom edge of the body. When the frame is assembled at the factory, sealant is injected into the void through a filling hole in the frame, and the sealant then flows into the two sealing channels to fill those regions. On the front of the body, the two sealing channels intersect at a centrally disposed cavity near the bottom edge of the body. Thus, during manufacture, injected sealant flows from the void into the two channels, through and along the channels from the back to the front, and then into the cavity on the front so as to seal off the open ends of the frame members at those locations and prevent the ingress of moisture.
The frame includes a flat, inwardly projecting glazing flange that is overlapped by the outer margin of a pane of glass or the like laid onto the non-decorative surface of the glazing flange. The area of overlap provides a marginal interior mounting surface for the pane. A bead of sealant along the entire rectangular trace of overlap securely attaches the pane to the frame and prevents moisture from entering under the pane.
One end of each member of the frame has a small notch in an upstanding, interior wall of the member near the miter joint that communicates the cavity at the front of the body with the non-decorative surface of the glazing flange. Therefore, when sealant is injected into a corner of the frame to fill the rear void, sealing channels, and front cavity, some of the sealant is forced out through the notch and onto the non-decorative surface of the glazing flange along the miter interface line. This xe2x80x9ctailxe2x80x9d of sealant can be manually spread along the length of the interface line on the non-decorative surface of the glazing flange before the bead of sealant for the window pane or other panel is then applied, thereby assuring that the pane is fully sealed along the miter.
Each deflection rib is yieldably resilient, allowing the corner lock to fit intimately into the frame members, compensating for variations in the frame members. Any amount of sealant which might escape past the ribs is minimal to the point of not leaking out the decorative side of the joint.